Folliculitis is the inflammation of infected hair follicles. They’re often infected with Staphylococcus aureus bacteria. It may occur anywhere on the skin. Folliculitis is common on the scalp where hair follicles are abundant.

Folliculitis begins as small, pimple-like bumps that spread and turn into crusty sores. Other symptoms may include:

pus-filled blisters that may erupt and ooze pus

itching

burning skin

pain

a large bump or mass

Anyone can get folliculitis. Your risk increases if any of the following apply:

you have a medical condition that suppresses the immune system, such as HIV or chronic leukemia

Call your doctor if you have symptoms of psoriasis. If you’ve received a psoriasis diagnosis, contact your doctor if:

you experience a widespread flare

your symptoms are worse than usual

you show signs of infection, such as fever, increased pain, or swelling

If you have an unexplained rash or suspect you have folliculitis, consult your doctor. Also seek medical help if you’ve received a folliculitis diagnosis and your symptoms recur frequently, worsen, or last longer than a few days.